limbic system [L, limbus, edge] , a group of structures within the rhinencephalon of the brain that are associated with various emotions and feelings such as anger, fear, sexual arousal, pleasure, and sadness. The structures of the limbic system include the cingulate gyrus, the isthmus, the hippocampal gyrus, the uncus, and the amygdala. The structures connect with various other parts of the brain such as the septum and the hypothalamus. Unless the limbic system is modulated by other cortical areas, periodic attacks of uncontrollable rage may occur in some individuals. The function of the system is incompletely understood.
